Apron type feeder



Patented Oct. 14, 1947 APRON TYPE FEEDER Alexander L. Munro, Milwaukee,Wis., assignor to Smith Engineering Works, Milwaukee, Wis., acorporation of Wisconsin A plicat on February 23, 1945, Serial No.579,442

The present invention relates in general to improvements in the art oftransporting material in bulk, and relates more especially toimprovements in the construction and operation of endless feeders of theapron type.

The principal object of my invention'istoprovide an improved apron typefeeder which is simple. and durable in construction, and which ismoreover highly eflicientin use.

Ithas long been customary in many industries, and especially in themining and crushing arts, to utilize so-called' apron feeders for thepurpose of continuously transporting diverse materials in bulk fromplace to'pla'ce. The prior apron type feeder ordinarily comprises anendless series of swingably interconnected flights cooperating to form aconstantly advancing approximately horizontal deck upon one end of whichthe bulk materialis deposited and from the opposite end of which thmaterial is discharged by gravity. In order to prevent theadvancingmaterial from dropping off of the sidesfof the travelling deck,the flights were sometimes provided with side walls which in some caseswere adapted to coact so as to prevent sagging of the transportingstretch or deck of the conveyor; but none of these prior apron feedersincorporated proper provision for adequately protecting the pivotalconnections between the successive flights, for preventing material fromdropping through the upperdeckonto the lower return stretch, andfor'resisting distortion due to excessive loading of the materialsupporting deck. The prior feeders of this type were also relativelycomplicated and could not be'durably and conveniently manufactured atmode-rate cost, thus making them objectionable for diverse reasons;

It is therefore a more specific object of the present invention 'toprovide an improved endless apron-feeder which overcomes the variousobjections above referred to; and which is adapted to be readilymanufactured and assembled as a compact and effective feed unit.

Another specific object of this invention is to provide an improvedflight structure for apron feeders, which may be easily constructed byordinary casting methods and with minimum machining, and which ismoreover built to positively prevent fine particles of material fromdropping through the material transporting deck during normal, use of anassembled group of the flights.

A further-specific object of my invention is to provide a simplifiedcastmetal conveyor flight which while beingrelatively light in weight,is exceedingly durable and rigid in construction thus adapting theseflights, to effectively resist bending and other distortion due toexcessive loadingof feeders embodying these flights,

Still another specific object of the present invention is to provide animproved endless conveying unit adapted'to effectively transport diverserelatively heavy mixed fine and coarse materials of various kinds, whichpresents an attractive and highly finished appearance, while requirr ingminimum power during normal efficient use thereof.

These and other specific objects and advantages of the invention will beapparent from the following detailed description.

A clear conception of the improved features involved in my presentinvention, and of the mode of constructing the improved feeder flights,of assembling the same, and of operating the'azsembled feeder units, maybe had by referring to the drawing accompanying and forming a part ofthis specification in which like reference characters designate the sameor similar parts in the various views.

Fig. 1 is a perspective view of one of my improved endless apron typefeeder units, looking toward one side and the discharge end thereof;

Fig. '2 is an enlarged fragmentary top view of several successivepivotally connected flights of the apron feeder, showing fragments ofthe pivot shafts which swingably interconnect the flights and alsoshowing the driving collars carried by these shafts; and

Fig. 3 is a partial side elevation and section through the flights ofFig. 2, showing one flight in elevation and two others in section takenjust inside of the adjacent side walls, and also showing one of the decksupporting rollers coacting with the lower edges of the flight sidewalls.

While the invention has been shown herein as being advantageouslyapplicable to apron feeders of the endless type especially adapted forheavy loading, it is not my desire or intent to unnecessarily restrictthe scope or utility of the improvement by virtue of this limiteddisclosure.

The improved apron feeder shown in the drawing by way of illustration,comprises in general an endless series of sturdy flights 5 swingablyinterconnected by means of pivot shafts 6 and adapted to be driven bysprocket wheels 1 coacting with rotatable collars 8 carried by theprotruding opposite ends of the shafts B, so as to cause theupperapproximately horizontal stretch or deck 9 of the endless series, toconstantly advance in a predetermined direction, as clearly shown inFig. 1. Each of the flights 5 is preferably formed of some suitable wearresistant material such as cast manganese steel, and consists primarilyof a transversely elongated imperforate flat deck portion or body l0having integral upstanding flanges or walls I I at its opposite sides,and being provided with integral hub portions l2, [3 at its oppositeends and beneath the body H! which have holes for pivotal coaction withthe shafts 6. The front hub portions l2 of each flight 5 are spacedapart for the intervening reception of the similarly spaced rear hubportions l3 of the next adjacent or following flight of the series, sothat the cooperating hub portions l2,- l3 of each set form anuninterrupted hub extending throughout the width of the feeder; and theupper or outer faces of the flight bodies iii are additionally providedwith local integral return guide ribs it, while the lower portions ofthese bodies are moreover provided with longitudinal and transverseintegral re-enforcing ribs l5 connecting the hub portions l2, l3 as wellas each other, see Figs. 2 and 3.

The integral side walls H of each flight 5 are provided with offsettrailing end portions it which are adapted to overlap the adjacent sidewalls l i of the adjoining flights 5 in order to avoid gaps betweenthese adjacent walls when the flights proceed around a bend, and whenthe flights 5 are travelling along the upper stretch 9 of the apron, thefront upper ends of the side walls ll of each flight are adapted tocontact abutments i! formed at the junctions between the rear ends ofthe side walls and the trailing portions 16 of the adjacent flights,thereby maintaining the stretch or upper deck 9 in straight linecondition and preventing downward sagging thereof. How ever, in order torelieve the shafts 6 from excessive stress due to loading of the stretch9, the lower edges l3 of all of the side walls l l are formed forrectilinear alinement with each other when active, and sup-portingrollers l9 are caused to contact these straight wall edges at intervals,as clearly illustrated in Figs. 1 and 3.

In accordance with my present invention, the front end of each flight 5is also provided with an integral curved lip 2ft extending entirelythereacross between the opposite side walls ll thereof and forming anarcuate recess 2| extending entirely across the endless feeder above thefront hub produced by the cooperating portions l2, l3;

and the rear end of each flight is furthermore provided with an integralarcuate rearwardly overhanging tongue 22 extending from one side walltrailing end portion 15 to the other, see Fig. 3. The tongues 22 areadapted to snugly fit within and to articulate in the recesses 2! of theadjacent flights 5 when the endless apron travels about its bends, andbesides materially strengthening and re enforcing the flights againstpossible distortion and sagging, the curved lips 29, tongues 22,recesses 2i positively prevent material from dropping through the upperdeck 9 of the endless conveyor, and thus protect the shafts e fromexcessive wear. The individual flights 5 are therefore formed of greatstrength, and may be readily produced of durable steel by casting andwithout requiring costly, machining for their ultimate completion.

The collars 8 are freely rotatably mounted upon the projecting ends ofthe pivot shafts S, and the driving sprockets l which are adapted toengage these collars 8 as indicated in Fig. 1, are mounted upon drivingand idler shafts 23, 24 respectively mounted in suitable bearings 25carried by a main supporting frame 26. The front driving shaft 23 alsocarries a gear 2']! which meshes with a driving pinion 23; and thesupporting rollers is which coact with the lower edges i8 of the flightwalls i l of the upper stretch 9, are also journalled in bearings 29mounted upon the frame 26 and pass transversely through the endlessapron between the upper and lower stretches thereof. In order to preventexcessive sagging of the lower idle stretch of the endless apron, thereturn guide ribs M which are formed integral with the outer surfaces ofthe flight bodies ill, are caused to smoothly coact with local sagpreventing rollers 38 which are likewise carried by a shaft 31journalled on the main frame 26, so that the entire apron assemblageconstitutes a unit all parts of which are associated with the commonframe 25,

As previously indicated, the individual flights 5 because of theirsimplicity may be readily constructed of durable steel or the like byordinary foundry methods, and no machining whatever is required fortheir production since the openings or holes in the hub portions l2, l3and which ultimately coact with the pivot shafts 6, may be formed bycoring. After proper construction and finishing of the flights 5 so thatall flights of a predetermined type are interchangeably similar,

any desired number of the unitary finished flights may be assembled intoan apron feeder of any suitable length and mounted upon a frame 26 asdepicted in Fig. 1. The feeder assemblage may thereafter be operated atwill by applying power from the driving pinion 28 to the gear 2". anddrive shaft 23; and during normal operation of the feeding unit, thesuccessive flights 5 of the endless series will constantly advance alongthe upper deck 9 in approximately horizontal and rectilinear formation,and will effectively convey bulk material from left to right as viewedin Fig. l, eventually delivering the mass of material over the dischargeend of the structure laterally adjacent to the gear 27.

During the advancement of the flights 5 along the upper deck 9, theabutments I 'l of the side walls ll of the leading flights cooperatewith the front ends of the side walls H and with the forwardly advancinglips 20 of the adjacent flights to prevent sagging of the upper stretchor deck 9 and to also relieve the pivot shafts 5 from excessivepressure, due to loading. The local supporting rollers l9 which coactwith the lower rectilinear edges [8 of the side walls I I, also serve toprevent sagging of the advancing upper deck 9, but since the arcuatelips 29 and the curved tongues 22 assist the abutments H in performingtheir function by preventing possible spreading of the portions of theside walls H which are integrally united by these lips and tongues, onlyrelatively few if any of the rollers H) are necessary. The coacting lips21] and tongues 22 besides aiding in the prevention of this sagging,also greatly enhance the transverse strength of the bodies I0, andfurthermore positively prevent finer material from dropping through theupper conveying deck 9 onto the shafts 6 and the lower return stretch ofthe endless apron. During rearward travel of this lower stretch, thelocal rollers so located beneath the apron, coact with the outer guideribs M of the successive flights 5, and thus also relieve the shafts 6from excessive pressure due to sagging of the return stretch; and therear portions iii of the side walls I I of the leading flights 5 overlapthe front portions of the opposite side walls of the succeeding flightsso as to eliminate side spillage of loose material. When the successiveflights 5 travel around the end bends, the rearwardly extending sidewall overlapping portions it also prevent the formation of gaps at thesides of the conveyor, and the lips 2i) and tongues '22 should also beof sufflcient length to prevent the formation of openings between theadjoining flights 5 at the bends.

From the foregoing detailed description of the construction andoperation of the improved assemblage, it should be apparent that mypresent invention provides an improved apron feeder wherein the flightmay be readily manufactured by ordinary foundry methods and at moderatecost, to produce extremely rigid, durable, and efficient individual andassembled flight units. Each of the improved flights 5 constitutes aunitary structure which is interchangeable with all others, and when agroup of the flights is assembled, a self-sustaining and imperviousmaterial carrying and transporting deck 9 results. The coacting arcuatelips 20 and tongues 22 of the pivotally connected flights 5, not onlyserve to prevent fine material from dropping through the conveying deck,but also firmly unite the opposite side walls II and overlappingportions 16 of each flight 5 and furthermore re-enforce the flightbodies l0 and prevent possible distortion thereof. The cross ribs l5 andthe guide rib l4 additionally strengthen the bodies l0, and the sidewalls II and projections 16 formed integral therewith function toeffectively confine the bulk material upon the conveying surface andprevent lateral spillage. The improved flights 5 may be manufactured indiverse sizes and shapes in order to meet varying operating conditionsand capacities, and if produced by casting, they require minimummachining and are relatively inexpensive. The improved apron feeder hasproven highly satisfactory and eflicient in actual use, may beconstructed of relatively light weight but of great strength, andpresents a neat and highly finished final appearance as will be apparentfrom Fig. 1.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode of operationherein shown and described, for various modifications within the scopeof the appended claims may occur to persons skilled in the art.

I claim:

1. An apron feeder, comprising, a series of articulably end connectedunitary flights each having a flat body provided with integralupstanding side walls projecting rearwardly beyond the body and coactingwith the walls of adjoining flights to provide endless flight supportingedges, each flight also having an overhanging tongue formed integralwith and spanning the space between said rearwardly projecting wallportions, the front portion of each body also being provided with acontinuous arcuate recess for the snu reception and articulation of saidtongue of an adjacent flight therein, supporting rollers for said seriesrotatable about fixed axes and coacting with said wall edges, andadvancing collars for said series carried by said flights outwardlybeyond said walls.

2. An apron feeder, comprising, a series of end connected unitaryflights each having a body provided with integral upstanding oppositeside walls adapted to abut against the walls of adjoining flights toprovide continuous flight supporting edges, said walls of each flightbeing integrally connected by an arcuate overhanging tongue extendingacross the trailing end of the body, said body also being provided atits front end with an arcuate recess for the snug reception andarticulation of said tongue of an adjacent flight therein, supportingrollers rotatable about fixed axes and coacting with said wall edges,pivot shafts connecting the successive flights, and advancing c01- larsfor said series carried by the outer ends of said shafts outwardlybeyond said flight walls.

3. An apron feeder, comprising, a series of articulably end connectedunitary flights each having a flat body provided with integralupstanding side walls projecting rearwardly beyond the body and adaptedto overlap the walls of adjoining flights to provide endless flightsupporting edges, each flight also having a rearwardly extending tongueformed integral with and spanning the space between said rearwardlyprojecting wall portions, the front portion of each body also beingprovided with an arcuate recess for the snug reception and articulationof said tongue of an adjacent flight therein, supporting rollers forsaid series rotatable aboutflxed axes and coacting with said wall edges,and advancing collars for said series carried by said flights outwardlybeyond said rearwardly projecting Wall portions.

4. An apron feeder, comprising, a series of end connected unitaryflights each having a body provided with integral upstanding oppositeside walls projecting rearwardly beyond the body and adapted to abutagainst and to overlap the walls of an adjoining flight to providecontinuous flight supporting edges, the rearwardly projecting portionsof said walls of each flight being integrally connected by an arcuatetongue extending across the trailing end of the body, said body alsobeing provided at its front end with an arcuate recess for the snugreception and articulation of said tongue of an adjacent flight therein,supporting rollers rotatable about fixed axes and coacting with saidwall edges, pivot shafts connecting the successive flights, andadvancing collars for said series carried by the outer ends of saidshafts outwardly beyond said rearwardly projecting wall portions.

5. An apron feeder, comprising, a series of articulably end connectedunitary flights each having a body provided with integral upstandingopposite side walls adapted to abut against and to overlap the Walls ofan adjoining flight to provide continuous flight supporting edges and acontinuous intervening material confining trough, said walls of eachflight being integrally interconnected by an arcuate rearwardlyextending tongue extending across the trailing end of its body, the bodyof each flight also being provided at its leading end with an arcuaterecess for snu reception and articulation of said tongue of an adjacentflight therein, supporting rollers rotatable about fixed axes andcoacting with said wall edges, pivot shafts articulably connecting thesuccessive flights near said tongues and recesses, and advancing collarsfor said series carried by the outer ends of each of said shaftsoutwardly beyond said flight Walls.

ALEXANDER L. MUNRO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 711,993 Mason Oct. 28, 1902886,343 Bevan May 5, 1908 1,804,423 Krenze May 12, 1931 1,854,334 Jensenet al. Apr. 19, 1932 FOREIGN PATENTS Number Country Date 561,616 GermanyOct. 15, 1932

